1. Field of Invention
The present invention relates to display devices.
2. Description of Related Art
Existing solutions for LED backlighting use either individually controlled LEDs, or a cluster of LEDs controlled as an individual unit. In each case, each LED is presented with a voltage and currents substantially identical to every other LED.
The diffused light output, or PSF, is essentially predetermined by the emissive pattern of an individual LED. As shown in FIG. 1, a single LED 100 produces a fixed light emission patter (LED light) 110. The LED light is incident, for example, on optical films 120, resulting in the production of a shaped light output, or PSF 130 (pattern of diffused light). The PSF 130 is essentially constant, but may vary in intensity according to modulation or a brightness level energizing the LED.
A similar result occurs when using light source clusters. FIG. 2 is an example of an LED cluster 200 that results is a PSF 250. Here, the PSF 250 is mainly composed of an aggregate of light from the LED cluster 200. The PSF 250 has a different shape, but again is essentially constant with a varying intensity.